diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,114 +1,147 @@
-# This file has been generated -- see https://github.com/hvr/multi-ghc-travis
+# This Travis job script has been generated by a script via
+#
+#   runghc make_travis_yml_2.hs '-o' '.travis.yml' '--irc-channel=irc.freenode.org#haskell-lens' '--no-no-tests-no-bench' '--no-installed' 'cabal.project'
+#
+# For more information, see https://github.com/hvr/multi-ghc-travis
+#
 language: c
 sudo: false
 
+git:
+  submodules: false  # whether to recursively clone submodules
+
+notifications:
+  irc:
+    channels:
+      - "irc.freenode.org#haskell-lens"
+    skip_join: true
+    template:
+      - "\x0313bifunctors\x03/\x0306%{branch}\x03 \x0314%{commit}\x03 %{build_url} %{message}"
+
 cache:
   directories:
-    - $HOME/.cabsnap
     - $HOME/.cabal/packages
+    - $HOME/.cabal/store
 
 before_cache:
   - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.tar
+  # remove files that are regenerated by 'cabal update'
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.*
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/*.json
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.cache
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar.idx
 
+  - rm -rfv $HOME/.cabal/packages/head.hackage
+
 matrix:
   include:
-    - env: CABALVER=1.18 GHCVER=7.0.4
-      compiler: ": #GHC 7.0.4"
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.0.4], sources: [hvr-ghc]}}
-    - env: CABALVER=1.18 GHCVER=7.2.2
-      compiler: ": #GHC 7.2.2"
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.2.2], sources: [hvr-ghc]}}
-    - env: CABALVER=1.18 GHCVER=7.4.2
-      compiler: ": #GHC 7.4.2"
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.4.2], sources: [hvr-ghc]}}
-    - env: CABALVER=1.18 GHCVER=7.6.3
-      compiler: ": #GHC 7.6.3"
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.6.3], sources: [hvr-ghc]}}
-    - env: CABALVER=1.18 GHCVER=7.8.4
-      compiler: ": #GHC 7.8.4"
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4], sources: [hvr-ghc]}}
-    - env: CABALVER=1.22 GHCVER=7.10.3
-      compiler: ": #GHC 7.10.3"
-      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.3], sources: [hvr-ghc]}}
-    - env: CABALVER=1.24 GHCVER=8.0.2
-      compiler: ": #GHC 8.0.2"
-      addons: {apt: {packages: [cabal-install-1.24,ghc-8.0.2], sources: [hvr-ghc]}}
-    - env: CABALVER=2.0 GHCVER=8.2.2
-      compiler: ": #GHC 8.2.2"
-      addons: {apt: {packages: [cabal-install-2.0,ghc-8.2.2], sources: [hvr-ghc]}}
-    - env: CABALVER=head GHCVER=head
-      compiler: ": #GHC head"
-      addons: {apt: {packages: [cabal-install-head,ghc-head], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.0.4"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.0.4], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.2.2"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.2.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.4.2"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.4.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.6.3"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.6.3], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.8.4"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.8.4], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.10.3"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.10.3], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.0.2"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-8.0.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.2.2"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-8.2.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.4.1"
+      env: GHCHEAD=true
+      addons: {apt: {packages: [*apt_packages,cabal-install-head,ghc-8.4.1], sources: [hvr-ghc]}}
+    - compiler: "ghc-head"
+      env: GHCHEAD=true
+      addons: {apt: {packages: [*apt_packages,cabal-install-head,ghc-head], sources: [hvr-ghc]}}
 
   allow_failures:
-    - env: CABALVER=1.18 GHCVER=7.0.4
-    - env: CABALVER=1.18 GHCVER=7.2.2
-    - env: CABALVER=head GHCVER=head
+    - compiler: "ghc-7.0.4"
+    - compiler: "ghc-7.2.2"
+    - compiler: "ghc-8.4.1"
+    - compiler: "ghc-head"
 
 before_install:
- - unset CC
- - export PATH=$HOME/.cabal/bin:/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
+  - HC=${CC}
+  - HCPKG=${HC/ghc/ghc-pkg}
+  - unset CC
+  - ROOTDIR=$(pwd)
+  - mkdir -p $HOME/.local/bin
+  - "PATH=/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$HOME/local/bin:$PATH"
+  - HCNUMVER=$(( $(${HC} --numeric-version|sed -E 's/([0-9]+)\.([0-9]+)\.([0-9]+).*/\1 * 10000 + \2 * 100 + \3/') ))
+  - echo $HCNUMVER
 
 install:
- - cabal --version
- - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
- - if [ -f $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz ];
-   then
-     zcat $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz >
-          $HOME/.cabal/packages/hackage.haskell.org/00-index.tar;
-   fi
- - travis_retry cabal update -v
- - sed -i 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config
- - cabal install --only-dependencies --enable-tests --dry -v > installplan.txt
- - sed -i -e '1,/^Resolving /d' installplan.txt; cat installplan.txt
+  - cabal --version
+  - echo "$(${HC} --version) [$(${HC} --print-project-git-commit-id 2> /dev/null || echo '?')]"
+  - BENCH=${BENCH---enable-benchmarks}
+  - TEST=${TEST---enable-tests}
+  - HADDOCK=${HADDOCK-true}
+  - INSTALLED=${INSTALLED-true}
+  - GHCHEAD=${GHCHEAD-false}
+  - travis_retry cabal update -v
+  - "sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config"
+  - rm -fv cabal.project cabal.project.local
+  # Overlay Hackage Package Index for GHC HEAD: https://github.com/hvr/head.hackage
+  - |
+    if $GHCHEAD; then
+      sed -i.bak 's/-- allow-newer:.*/allow-newer: *:base, *:template-haskell, *:ghc, *:Cabal/' ${HOME}/.cabal/config
 
-# check whether current requested install-plan matches cached package-db snapshot
- - if diff -u installplan.txt $HOME/.cabsnap/installplan.txt;
-   then
-     echo "cabal build-cache HIT";
-     rm -rfv .ghc;
-     cp -a $HOME/.cabsnap/ghc $HOME/.ghc;
-     cp -a $HOME/.cabsnap/lib $HOME/.cabsnap/share $HOME/.cabsnap/bin $HOME/.cabal/;
-   else
-     echo "cabal build-cache MISS";
-     rm -rf $HOME/.cabsnap;
-     mkdir -p $HOME/.ghc $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin;
-     cabal install -j --only-dependencies --enable-tests;
-   fi
+      echo 'repository head.hackage'                                                        >> ${HOME}/.cabal/config
+      echo '   url: http://head.hackage.haskell.org/'                                       >> ${HOME}/.cabal/config
+      echo '   secure: True'                                                                >> ${HOME}/.cabal/config
+      echo '   root-keys: 07c59cb65787dedfaef5bd5f987ceb5f7e5ebf88b904bbd4c5cbdeb2ff71b740' >> ${HOME}/.cabal/config
+      echo '              2e8555dde16ebd8df076f1a8ef13b8f14c66bad8eafefd7d9e37d0ed711821fb' >> ${HOME}/.cabal/config
+      echo '              8f79fd2389ab2967354407ec852cbe73f2e8635793ac446d09461ffb99527f6e' >> ${HOME}/.cabal/config
+      echo '   key-threshold: 3'                                                            >> ${HOME}/.cabal.config
 
-# snapshot package-db on cache miss
- - if [ ! -d $HOME/.cabsnap ];
-   then
-      echo "snapshotting package-db to build-cache";
-      mkdir $HOME/.cabsnap;
-      cp -a $HOME/.ghc $HOME/.cabsnap/ghc;
-      cp -a $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin installplan.txt $HOME/.cabsnap/;
-   fi
+      cabal new-update head.hackage -v
+    fi
+  - grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$'
+  - "printf 'packages: \".\"\\n' > cabal.project"
+  - cat cabal.project
+  - if [ -f "./configure.ac" ]; then
+      (cd "." && autoreconf -i);
+    fi
+  - rm -f cabal.project.freeze
+  - cabal new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
+  - rm -rf "."/.ghc.environment.* "."/dist
+  - DISTDIR=$(mktemp -d /tmp/dist-test.XXXX)
 
 # Here starts the actual work to be performed for the package under test;
 # any command which exits with a non-zero exit code causes the build to fail.
 script:
- - cabal configure -v2 --enable-tests  # -v2 provides useful information for debugging
- - cabal build # this builds all libraries and executables (including tests/benchmarks)
- - cabal test --show-details=always
- - cabal haddock
- - cabal sdist   # tests that a source-distribution can be generated
- - export SRC_TGZ=$(cabal info . | awk '{print $2 ".tar.gz";exit}') ;
-   cd dist/;
-   if [ -f "$SRC_TGZ" ]; then
-      cabal install "$SRC_TGZ";
-   else
-      echo "expected '$SRC_TGZ' not found";
-      exit 1;
-   fi
+  # test that source-distributions can be generated
+  - (cd "." && cabal sdist)
+  - mv "."/dist/bifunctors-*.tar.gz ${DISTDIR}/
+  - cd ${DISTDIR} || false
+  - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
+  - "printf 'packages: bifunctors-*/*.cabal\\n' > cabal.project"
+  - cat cabal.project
 
-notifications:
-  irc:
-    channels:
-      - "irc.freenode.org#haskell-lens"
-    skip_join: true
-    template:
-      - "\x0313bifunctors\x0f/\x0306%{branch}\x0f \x0314%{commit}\x0f %{message} \x0302\x1f%{build_url}\x0f"
 
+  # build & run tests, build benchmarks
+  - cabal new-build -w ${HC} ${TEST} ${BENCH} all
+  - if [ "x$TEST" = "x--enable-tests" ]; then cabal new-test -w ${HC} ${TEST} ${BENCH} all; fi
+
+  # cabal check
+  - (cd bifunctors-* && cabal check)
+
+  # haddock
+  - rm -rf ./dist-newstyle
+  - if $HADDOCK; then cabal new-haddock -w ${HC} ${TEST} ${BENCH} all; else echo "Skipping haddock generation";fi
+
+# REGENDATA ["-o",".travis.yml","--irc-channel=irc.freenode.org#haskell-lens","--no-no-tests-no-bench","--no-installed","cabal.project"]
 # EOF
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,5 +1,9 @@
+5.5.1 [2018.02.04]
+------------------
+* Test suite fixes for GHC 8.4.
+
 5.5 [2017.12.07]
----
+----------------
 * `Data.Bifunctor.TH` now derives `bimap`/`bitraverse`
   implementations for empty data types that are strict in the argument.
 * `Data.Bifunctor.TH` no longer derives `bifoldr`/`bifoldMap` implementations
diff --git a/bifunctors.cabal b/bifunctors.cabal
--- a/bifunctors.cabal
+++ b/bifunctors.cabal
@@ -1,6 +1,6 @@
 name:          bifunctors
 category:      Data, Functors
-version:       5.5
+version:       5.5.1
 license:       BSD3
 cabal-version: >= 1.8
 license-file:  LICENSE
@@ -11,9 +11,9 @@
 bug-reports:   http://github.com/ekmett/bifunctors/issues
 copyright:     Copyright (C) 2008-2016 Edward A. Kmett
 synopsis:      Bifunctors
-description:   Bifunctors
+description:   Bifunctors.
 build-type:    Simple
-tested-with:   GHC == 7.0.4, GHC == 7.2.2, GHC == 7.4.2, GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2
+tested-with:   GHC == 7.0.4, GHC == 7.2.2, GHC == 7.4.2, GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.1
 extra-source-files: .travis.yml CHANGELOG.markdown README.markdown
 
 source-repository head
@@ -95,6 +95,7 @@
   main-is: Spec.hs
   other-modules: BifunctorSpec
   ghc-options: -Wall
+  build-tool-depends: hspec-discover:hspec-discover >= 1.8
   build-depends:
     base                >= 4   && < 5,
     bifunctors,
diff --git a/src/Data/Bifunctor/TH/Internal.hs b/src/Data/Bifunctor/TH/Internal.hs
--- a/src/Data/Bifunctor/TH/Internal.hs
+++ b/src/Data/Bifunctor/TH/Internal.hs
@@ -422,12 +422,6 @@
 bitraverseConstValName :: Name
 bitraverseConstValName = mkBifunctorsName_v "Data.Bifunctor.TH.Internal" "bitraverseConst"
 
-dualDataName :: Name
-dualDataName = mkNameG_d "base" "Data.Monoid" "Dual"
-
-endoDataName :: Name
-endoDataName = mkNameG_d "base" "Data.Monoid" "Endo"
-
 wrapMonadDataName :: Name
 wrapMonadDataName = mkNameG_d "base" "Control.Applicative" "WrapMonad"
 
@@ -440,9 +434,6 @@
 traversableTypeName :: Name
 traversableTypeName = mkNameG_tc "base" "Data.Traversable" "Traversable"
 
-appEndoValName :: Name
-appEndoValName = mkNameG_v "base" "Data.Monoid" "appEndo"
-
 composeValName :: Name
 composeValName = mkNameG_v "base" "GHC.Base" "."
 
@@ -464,9 +455,6 @@
 foldMapValName :: Name
 foldMapValName = mkNameG_v "base" "Data.Foldable" "foldMap"
 
-getDualValName :: Name
-getDualValName = mkNameG_v "base" "Data.Monoid" "getDual"
-
 seqValName :: Name
 seqValName = mkNameG_v "ghc-prim" "GHC.Prim" "seq"
 
@@ -555,4 +543,30 @@
 
 bitraverseValName :: Name
 bitraverseValName = mkBifunctorsName_v "Data.Bitraversable" "bitraverse"
+#endif
+
+#if MIN_VERSION_base(4,11,0)
+appEndoValName :: Name
+appEndoValName = mkNameG_v "base" "Data.Semigroup.Internal" "appEndo"
+
+dualDataName :: Name
+dualDataName = mkNameG_d "base" "Data.Semigroup.Internal" "Dual"
+
+endoDataName :: Name
+endoDataName = mkNameG_d "base" "Data.Semigroup.Internal" "Endo"
+
+getDualValName :: Name
+getDualValName = mkNameG_v "base" "Data.Semigroup.Internal" "getDual"
+#else
+appEndoValName :: Name
+appEndoValName = mkNameG_v "base" "Data.Monoid" "appEndo"
+
+dualDataName :: Name
+dualDataName = mkNameG_d "base" "Data.Monoid" "Dual"
+
+endoDataName :: Name
+endoDataName = mkNameG_d "base" "Data.Monoid" "Endo"
+
+getDualValName :: Name
+getDualValName = mkNameG_v "base" "Data.Monoid" "getDual"
 #endif
diff --git a/tests/BifunctorSpec.hs b/tests/BifunctorSpec.hs
--- a/tests/BifunctorSpec.hs
+++ b/tests/BifunctorSpec.hs
@@ -200,14 +200,31 @@
 instance (Bifunctor (f Int), Functor g) =>
   Bifunctor (ComplexConstraint f g) where
     bimap = $(makeBimap ''ComplexConstraint)
+
 instance (Bifoldable (f Int), Foldable g) =>
   Bifoldable (ComplexConstraint f g) where
     bifoldr   = $(makeBifoldr ''ComplexConstraint)
     bifoldMap = $(makeBifoldMap ''ComplexConstraint)
+
+bifoldlComplexConstraint
+  :: (Bifoldable (f Int), Foldable g)
+  => (c -> a -> c) -> (c -> b -> c) -> c -> ComplexConstraint f g a b -> c
+bifoldlComplexConstraint = $(makeBifoldl ''ComplexConstraint)
+
+bifoldComplexConstraint
+  :: (Bifoldable (f Int), Foldable g, Monoid m)
+  => ComplexConstraint f g m m -> m
+bifoldComplexConstraint = $(makeBifold ''ComplexConstraint)
+
 instance (Bitraversable (f Int), Traversable g) =>
   Bitraversable (ComplexConstraint f g) where
     bitraverse = $(makeBitraverse ''ComplexConstraint)
 
+bisequenceAComplexConstraint
+  :: (Bitraversable (f Int), Traversable g, Applicative t)
+  => ComplexConstraint f g (t a) (t b) -> t (ComplexConstraint f g a b)
+bisequenceAComplexConstraint = $(makeBisequenceA ''ComplexConstraint)
+
 $(deriveBifunctor     ''Universal)
 
 $(deriveBifunctor     ''Existential)
@@ -250,13 +267,30 @@
 instance (Bifunctor (f Int), Functor g) =>
   Bifunctor (ComplexConstraintFam f g) where
     bimap = $(makeBimap 'ComplexConstraintFam)
+
 instance (Bifoldable (f Int), Foldable g) =>
   Bifoldable (ComplexConstraintFam f g) where
     bifoldr   = $(makeBifoldr 'ComplexConstraintFam)
     bifoldMap = $(makeBifoldMap 'ComplexConstraintFam)
+
+bifoldlComplexConstraintFam
+  :: (Bifoldable (f Int), Foldable g)
+  => (c -> a -> c) -> (c -> b -> c) -> c -> ComplexConstraintFam f g a b -> c
+bifoldlComplexConstraintFam = $(makeBifoldl 'ComplexConstraintFam)
+
+bifoldComplexConstraintFam
+  :: (Bifoldable (f Int), Foldable g, Monoid m)
+  => ComplexConstraintFam f g m m -> m
+bifoldComplexConstraintFam = $(makeBifold 'ComplexConstraintFam)
+
 instance (Bitraversable (f Int), Traversable g) =>
   Bitraversable (ComplexConstraintFam f g) where
     bitraverse = $(makeBitraverse 'ComplexConstraintFam)
+
+bisequenceAComplexConstraintFam
+  :: (Bitraversable (f Int), Traversable g, Applicative t)
+  => ComplexConstraintFam f g (t a) (t b) -> t (ComplexConstraintFam f g a b)
+bisequenceAComplexConstraintFam = $(makeBisequenceA 'ComplexConstraintFam)
 
 $(deriveBifunctor     'UniversalFam)